The US Air Force Research Laboratory (AFRL) is hoping to transition the SkyTote vertical take-off and landing (VTOL) unmanned air vehicle to partial and full horizontal flight in a new phase of forthcoming tests in California, following the completion of initial autonomous hover tests at the Yuma Proving Grounds, Arizona.
The SkyTote is being developed by California-based AeroVironment under the second phase of an AFRL small business initiative research programme started in 1998. The tail-sitting, winged UAV is designed to provide simple, reliable and low-cost cargo transport for military users, although civil versions could also be developed. Potential users include US special forces and regular army units for bomb damage assessment, resupply or emergency troop evacuation, says AFRL.
The UAV takes off, hovers and lands like a helicopter using a pair of counter-rotating proprotors powered by a 50hp (40kW) UEL AR801 rotary engine. After take-off, the UAV is designed to transition to wing-borne flight supported by a 2.4m (8ft)-span wing and a 2.3m-span cruciform tail, which doubles as landing legs. The concept demonstrator, which is designed to carry a 23kg (50lb) payload over a radius of 280km (150nm), is expected to demonstrate hovering and conventional wing-borne flight as well as automated transitions between the two. The AFRL says “a pilot will be standing by to take control if needed. However, most of the testing will be controlled autonomously.”
The AFRL says several horizontal to VTOL transition manoeuvres are being considered, including a simple pop-up involving a fly-up, power back and hold with power; and a 1g stall followed by a full-power recovery.
GUY NORRIS / LOS ANGELES
Source: Flight International
